To remain competitive, a manufacturer must employ a quality control system capable of gathering information about each of the products it manufactures. One such quality control system includes one or more test systems coupled via a communication link to a host computer having a database. A shared file directory is employed by the host computer to negotiate communications between the test systems, the communication link, and the database. Each test system interfaces with a product and subjects the product to tests. Once the tests are concluded, the test system outputs a file containing test result data to the shared file directory. The host computer opens the file in the shared file directory, reads the test result data from the opened file, and inserts the test result data into the database. Aside from test result data provided by the test systems, the database also contains a plurality of other information about each product from other systems located in the manufacturing environment and visited by each of the products prior to delivery to the test systems. Such information includes model number data, test status data, repair data, defect data, or the like.
Unfortunately, the test systems only communicate unidirectionally--from the test system to the database--and can not retrieve previously stored product information. As a result, each of the products must employ a product identifier contained in, for example, a bar-code attached to the product. The product identifier includes a unique designator to differentiate one product from another and a model designator to designate the model of the product. An example of such a product identifier is "2TWP008", wherein "2TWP0" is the unique identifier and "08" designates the model. The test system obtains the product identifier during interfacing, extracts the model designator from the product identifier, and configures itself according to the model designator so as to test the product as that particular model. However, the use of product identifiers having model designators increases manufacturing costs because, for example, a separate set or roll of preprinted bar-codes must be specifically purchased for each model and is limited for use with only that model. The use of product identifiers having model designators also adds unwanted additional complexity to the manufacturing system. The data "stored" on each product (i.e., the model designator in the product identifier) duplicates that which must be maintained in the database.
Therefore, what is needed is an apparatus and method that permits bi-directional messaging between a test system and a database so as to allow the test system to retrieve product information, such as a model number, from the database in substantially real-time and, thereby, eliminating the need for information redundancy in the manufacturing system.